{
  "type": "File",
  "start": 0,
  "end": 44,
  "loc": {
    "start": {
      "line": 1,
      "column": 0
    },
    "end": {
      "line": 1,
      "column": 44
    }
  },
  "program": {
    "type": "Program",
    "start": 0,
    "end": 44,
    "loc": {
      "start": {
        "line": 1,
        "column": 0
      },
      "end": {
        "line": 1,
        "column": 44
      }
    },
    "sourceType": "module",
    "interpreter": null,
    "body": [
      {
        "type": "FunctionDeclaration",
        "start": 0,
        "end": 44,
        "loc": {
          "start": {
            "line": 1,
            "column": 0
          },
          "end": {
            "line": 1,
            "column": 44
          }
        },
        "id": {
          "type": "Identifier",
          "start": 9,
          "end": 12,
          "loc": {
            "start": {
              "line": 1,
              "column": 9
            },
            "end": {
              "line": 1,
              "column": 12
            },
            "identifierName": "foo"
          },
          "name": "foo"
        },
        "generator": false,
        "async": false,
        "params": [
          {
            "type": "Identifier",
            "start": 13,
            "end": 41,
            "loc": {
              "start": {
                "line": 1,
                "column": 13
              },
              "end": {
                "line": 1,
                "column": 41
              },
              "identifierName": "callback"
            },
            "name": "callback",
            "typeAnnotation": {
              "type": "TypeAnnotation",
              "start": 21,
              "end": 41,
              "loc": {
                "start": {
                  "line": 1,
                  "column": 21
                },
                "end": {
                  "line": 1,
                  "column": 41
                }
              },
              "typeAnnotation": {
                "type": "FunctionTypeAnnotation",
                "start": 23,
                "end": 41,
                "loc": {
                  "start": {
                    "line": 1,
                    "column": 23
                  },
                  "end": {
                    "line": 1,
                    "column": 41
                  }
                },
                "params": [
                  {
                    "type": "FunctionTypeParam",
                    "start": 24,
                    "end": 30,
                    "loc": {
                      "start": {
                        "line": 1,
                        "column": 24
                      },
                      "end": {
                        "line": 1,
                        "column": 30
                      }
                    },
                    "name": {
                      "type": "Identifier",
                      "start": 24,
                      "end": 25,
                      "loc": {
                        "start": {
                          "line": 1,
                          "column": 24
                        },
                        "end": {
                          "line": 1,
                          "column": 25
                        },
                        "identifierName": "_"
                      },
                      "name": "_"
                    },
                    "optional": false,
                    "typeAnnotation": {
                      "type": "BooleanTypeAnnotation",
                      "start": 26,
                      "end": 30,
                      "loc": {
                        "start": {
                          "line": 1,
                          "column": 26
                        },
                        "end": {
                          "line": 1,
                          "column": 30
                        }
                      }
                    }
                  }
                ],
                "rest": null,
                "returnType": {
                  "type": "NumberTypeAnnotation",
                  "start": 35,
                  "end": 41,
                  "loc": {
                    "start": {
                      "line": 1,
                      "column": 35
                    },
                    "end": {
                      "line": 1,
                      "column": 41
                    }
                  }
                },
                "typeParameters": null
              }
            }
          }
        ],
        "body": {
          "type": "BlockStatement",
          "start": 42,
          "end": 44,
          "loc": {
            "start": {
              "line": 1,
              "column": 42
            },
            "end": {
              "line": 1,
              "column": 44
            }
          },
          "body": [],
          "directives": []
        }
      }
    ],
    "directives": []
  }
}